By now most have received the Owner Advisory regarding the carburetor float. Does this affect those of us with the older carbs on 170's/172's?

Second question---when replacing the thermocouple for a cylinder head temp or exhaust temp indicator/gauge, is that an engine log or airframe log entry? Seems it should be engine since it deals with the engine, but I want to enter it in the correct logbook.

bagarre, I will defer the details of this to George, Bruce, Del, Brad or other's that will know the facts. I will say that I received my Owner Advisory sometime over the weekend while I was out of town. It is dated July 20, 2010 and states that Service Bulletin SEB10-3,: Carburetor Float Replacement-Continental Engine Airplanes, has been issued to transmit the Teledyne Continental Motors (TCM) Service Bulletins and Volare Carburetors Service Bulletins------. It has to do with Foam and Hollow Floats. Don't react until some of these folks clarify this for all of us. Thanks, Frank

Frank, the Owner Advisory to which you are inferring is merely a CYA action for Volare, who purchased mfr'g rights to the Precision Airmotive carb, (who purchsed it from Facet, who purchased it from Marvel-Schebler). In other words they're repeating themselves.

The satisfying action is compliance with AD 92-15-16 which replaced defective floats mfr'd by Consolodated Fuel systems PN CF30-766 dated "10 91". Any of the Precision Airmotive floats PN 30-766 are OK, as are any CFS floats with other dates.

The other concern with carbs is AD 98-01-06 which requires regular inspection of two-piece venturi... or replacement of that with a one-piece venturi, (and possible fuel nozzle change) which eliminates the repetitive inspection.

Volare is essentially telling Cessna to tell owners of the name change. If those two ADs are complied, then no further action is required.

Speaking of Volare, has anyone had any experience with AvStar carbs? They are apparently in competition with Volare and been chosen by Lycoming as their supplier. They use billet stock for their bodys and brass floats.(note: I notice on their web site they mention they are in Chap. 11 bankruptcy)

In regard to your second question, I have understood that if you replaced an item on the engine, such as a EGT Probe or Cylinder Temp Probe ie: any item attached to the engine, that would require a engine logbook entry.However if you change an instrument associated to the operation of that engine, that would be an aircraft logbook entry. Wes

Unless the engine TCDS specifies the accy, or is altered by the accy, it goes in the airframe log.

In the case of the CHT gauge, ... the only aircraft required to have CHT are those with cowl flaps. The CHT in Frank's installation is required neither by the engine TC nor the airframe, but it is an alteration of the airframe, so the unit is logged there. If the installation of a CHT probe required a cylinder change to accomodate a head-mounted probe, then both logbooks would be so noted, but future replacements of the probe would be airframe mx. (I doubt anyone would complain if it were entered in both logs but consider this: If you later replace that engine with another in an exchange program...would you remove that probe and install it on the new engine??? or would you send the old engine off to it's new owner with that probe still installed?? If the former...then it's clearly an airframe matter. If the latter is the case, then the probe will have to be logged off the airframe log and a new probe installation noted there. Considering those kinds of scenarios may help you understand where the log entry should go.